PROCESS AND APPARATUS FOR SWEETENING AND LIQUEFYING A GAS STREAM

摘要

A process and apparatus for liquefying a gas stream comprising hydrocarbons and sour species is provided in which the sour species are removed in liquefied form as the sweetened gas stream is progressively cooled to liquefaction temperatures. The process involves cooling the gas stream in a manner to produce a cooled gas stream comprising gaseous hydrocarbons and residual sour species. The cooled gas stream is then treated with a cold solvent to deplete the cooled gas stream of residual sour species. The resulting cooled sweetened gas stream is then further cooled to produce liquid hydrocarbons.

主权项

1. A process for liquefying a gas stream comprising hydrocarbons and sour species, the process comprising the steps of:
a) cooling the gas stream by heat exchange with a first refrigerant stream to a temperature marginally greater than at which solidification of the sour species occurs; b) further cooling the gas stream to a first temperature between about −80° C. to −95° C. at a pressure between about 15 to 25 bar by expanding the gas stream as it is introduced into a vessel to produce a mixture of solid and/or liquid sour species and a cooled gas stream comprising gaseous hydrocarbons and residual sour species; c) separating the solid and/or liquid sour species from the cooled gas stream in the vessel; d) contacting the cooled gas stream with a solvent under temperature conditions close to or at the first temperature to deplete the cooled gas stream of residual sour species, thereby producing a cooled sweetened gas stream; and e) cooling the cooled sweetened gas stream to a second temperature below the methane boiling point by heat exchange with a second refrigerant stream to produce liquid hydrocarbons.